Graphene, carbon nanotubes (CNTs), and spintronic logic have been suggested as replacements to silicon complementary logic as transistor scaling approaches its inherent limits. Carbon nanotube (CNT) and graphene nanoribbon (GNR) logic circuits have been fabricated for the conventional complementary metal-oxide-semiconductor (CMOS) logic family that take advantage of the fast switching speeds and high current density of low-dimensional carbon materials. Additionally, new logic families are enabled by spintronics, in which electron spin is manipulated along with electron charge to perform logical functions efficiently. Large leakage currents in graphene transistors have inhibited their use in the CMOS logic family, and spintronic circuit development has been hampered by the difficulty in cascading logic gates.